Blowing device for rock drills



March 21, 1933. L. c. BAYLES 1.9025

I BLOWING DEVICE FOR ROCK DRILLS Filed July 23, 1931 IN VEN TOR.

Patented Mar. 21, 1933 UNITED STATES PATENT oFFIcE-f LEwis 0. BAYLES, orEASTON, PENNSYLVANIA, AssIeNo t T mGEnsoLLRAm) COMPANY, or JERSEY CITY,new JERSEY, .A conrona'nonor maw JERSEY BLOWING DEVICE FOR ROCK pa nts"Application filed July 23, 1931. Serial Nb. 552,600.

This invention relates to rock drills, but more particularly to ablowing device for rocks drills of the fluid actuated type.

One object of the invention is toselective-' 5 1y admit pressure fluidunder full line pressure and in unrestricted quantities intothe drillhole 'to remove the cuttings therefrom andto simultaneously prevent thedelivery of blows against the workingimplement.

Other objects will be in part obvious and in part pointed outhereinafter.

In the accompanying drawing in which similar reference characters referto similar parts, a i I Figure 1 isa sectional elevation of a percussivetool having the invention applied thereto and showing the position ofthe parts during the blowing operation, 7

Figure 2 is a fragmentary view showing the position of the valve holdingdevice during the normalvo erationof the drillyand Figure 3 is an eevation insectio-n of a detail taken through Figure 1 on the line 3 3looking in the direction indicated by the arrows. y A V 7 Referring moe'particularly to the drawing; A designates generallyga rock drillof thehammer type comprising a cylinder B having a piston chamber Ctherein toaccommodate a reciprocatory hammer piston'D.

. i The piston D may be of a well known type having a head E s lidablein the piston chamber and controlling a free exhaust port F in thecylinder 13.. On the front end of V the piston D is an integral stem orextension 7 G having a series of flutes H to interlock with ribs Jcarried by a chuckK which is V encased by afront'headL. s H

The chuck K may rotate freely within the 40 front head L and is adaptedtoireceive the shank end of a hollow working implement O, such as adrillsteel, which may be suitably interlocked with the chuck in a well knownmanner to rotate therewith. A front cylinder washerP interposed betweenthe cylinder B and the front head L may extend with its ends into thecylinder and the front ,head and has a bore Q to serve as; a guide forthe extension G of the piston.

1 Seated on the rear end of the cylinder B is'an extension R having endwall at 5 its front or inner end to serve as a closure for, the rear endof the piston chamber "{C.

On the'rear end of the wall Sis a' surface T which acts as alseat'for.asdistributing valve 575 ,i Y

U of the oscillatory-plate'type arranged in 'a valve chamber-Y for whicha plate disposed in the extension R ward closure.

serves asarear- The valve Uis of a well knownftype'6 adapted tooscillate or rock from onelimite ing position to another to control thedistribution, of pressure fluid from the valve chamberV to the ends ofthe piston chamber C..- The admission of such pressure fluid intotherear end of the piston chamber for actuating the pistonf D' forwardlyconveyed thereto by a rear inlet passage X in the wall S; and a frontinlet passage VY formed in the wall'S and the cylinder B 71 serves toconvey pressure fluid. from} the valve chamber V tothe front end ofthepiston chamber- C for actuating the g D rearwardly.v

The rotation mechanismiemployed f o -75 imparting rotary movement to thechuck K r and the working implement O and desig nated generally by Zcomprises the usual rifle bar I) I which may extend into andinterlockingly' engage the piston Di'n a well known manner. A ratchetring] 0 seated on the rearend ofthe plate'W encircles a head d ontherifle 'bar to act'as an abutment for i spring pressed p'awls e; carriedtheheadd.

The admission of pressure fluid intofthel rock drill for actuating thepiston D may be controlled by a suitable throttle valve (not shown)andpasses intothe valve cham-- ber V through a supply passage shown,

for illustrative' purposes, as being located;

in the extension R; 5

The rock'drill A is further shown as being provided with a tube 9 'whichextends coaxially through-the'drillfrom the rear end thereof andextends. with its front end- 9 intothe working implement -O to conveycleansing fluid thereto for washing the cuttings fromthe drill hole. v

In accordance with the practice of the invention, means are provided forassuring an uninterrupted supply of pressure fluid to the drill steelwhenever the detritus tends to accumulate therein and which,if

not expelled from the drill hole, will form a collar of cuttingsadjacent the bit end or "the drill steel and seriously impede the Tothat action of the rotation'mechanism. 7 end the extens on R 1s providedwith a lateral projection 71, having a bore j, preferably of;cylindricalshape, for the accommodation of a ll-shaped spring is ofwhich the lowermost leg is the shorter leg'and seats with its edgesagainstthewall of the .wise movement of the spring [is in the directionof the valve chamber V wherewith the inner end of the bore'ycommunlcates.

-The upper leg 77 of' the spring 70 which isof greater length than theleg '0 extends into the valve chamber V and terminates at its free endin a hook s which is adapted to seatup on the rear surface of the valveU to :pressthatend of the valve firmly 'upon the seat T to cover theinlet passage X.

At the juncture of the" projection 7t and the extension R is a bore 6which communicates atan intermediate portion with the bore j and hasarranged thereina plug a of-the rotary type provided; with alever o forits manipulation; Inthe periphery of thepluguis an annular groove w of awidth to accommodatethe leg 1' of the spring, is which'extends into thegroove w and holds the plugu against endwise movement in the borej. f

In the side'of the plug u and in the same transverse plane as the grooveto is a re cess w having a flat bottomsurface-to seat upon'the leg randthus form'a wide areaof v contact' between the leg? and the: plugwhen the plug and the leg 1" are in the positions which they occupyduring, the normal 7 operation ofthe drill.

In order .to assure a suitablepressure in the rear end of the pistonchamber C so is provided with a passageyiwhich opens one end lllhOtherecess w and communicates at-its other end with ableederipassage a inend of the bore j in the form of, a plug I that ,the pressure, actingagainst :theffront end ofthe head Efof the piston will be unabletoactuate the pistoninto a position to .placethe efront end of thepiston chamber G in communicationewith the atmosphere through, the freeexhaust port F, the plug n the extension R and openinginto the rear endvof the piston chamber C. I

A closure may be provided'for the outer whichmay be secured totheprojection 1 in any suitable manner-,ss for instance by braing OrWeldingfas illustrated. v j

The operation of the device is as follows:

Upon the admission of'pressure fluid into the valve chamber V suchpressure fluid will normally be'distri uted by'the'valve U chamberalternately into communicationwith the atmosphere through the exhaustport F for exhausting the fluid utilized for actuating the piston.

During this operation of the tool a portion of pressure fluid will flowthrough the flutes H, thence through the drill steel 0 into.

the drill hole during each admission of pressure 'fluid to the front'end'of the piston chamber G and will remove the cuttings from the dril'lholei I As the depth of the drill hole increases it becomes increasinglydifficult to completely remove all the cuttings so that, in 'consequence,the cuttings will accumulate therein and bring aboutthe'unfavorab'le condition hereinb'efore referredto. Whenever it becomesapparent'that the alternatepuffs of pressure fluid issuin thepistonchamber 7 tain the drill hole. free, from cuttingsthe from the, frontend of do not suiflce to mainplug a may be rotated to the positionillustrated'in Figure lto depress'the leg? of the spring is. The hook swill then'seat' upon 'the'adjacent' end of the valve U to preventtheentrance of'pressurefluid from the valve iehamber into'the'inletpassage X.

The opposite end of the valve will then be fullyraised and pressurefluid will'flow from the valve chamber V through the front? inletpassage Yyand through the front end of the piston chamber C thencethrough the flutes Hand the drill steel 0' intothe drill hole todischarge the cuttingstherefrom. In the locking position "of the pluglathe passage 3 in the plug will-register with the passage a and willalso be in communication with the valve chamber V, pressure fluid willthen flow in restricted quantity, as compared with that flowing'throughthe pas-' sage Y, into the rear end of the piston chamber to maintain asuitable pressure therein to balance the pressure acting against theforward area or areas of the plston D.

quired position by the'f leg 1", which may be slightly flexed att h'epoint whereon the plug. u seats to assure a suitable pressure against Jthe plug for holding it immovable.

In tools wherein the piston is provided throughout its length with aboresuch as-is required to accommodate the rifle bar. and

the-water tube; a pressure balancingthat in 7 of pressure which mayaccumulate in the rear end of the piston chamber will. merely depressthe piston D sufliciently to slightly open the exhaust port F, whereuponsuch excess pressure fluid will escape andthe' piston D may thenimmediately return to 7 close the exhaust port F. In tools, however,

such as that illustrated wherein pressure fluid may pass through thepiston it has been found that the pressure fluld acting against theopposing end areas of the piston will be balanced and that the pistonwill therefore remain immovable during the blowing operation.

After thedrill hole has been thoroughly one leg seated upon the wall ofthe recess, a

plug in the casing to press the other legof the spring into engagementwith the valve forholding said valve in position tosupply l pressurefluid to the front end of the piston chamber and to the blower passage,said valve having a groove to receive the last said leg of the springand whereby the plug is retained in the casing, and passages in the plugand the casing to admit pressure fluid into the rear end of the pistonchamberj during the blowing operation to maintain the piston in anintermediate position in the piston chamberfor. closing the exhaustport.

In testimony whereof I have signed this specification. a I

LEWIS ognAvnns,

cleansed the plug it may again be rotated to permit the leg 1 to moveout of the path of the valve U and the leg 1', owing to its inherentresiliency, will then press against the bottom of the recess m andmaintain the plug it immovable during the subsequent operation of thetool.

I claim:

1. A fluid actuated rock drill comprising a a casing having a pistonchamber and an exhaust port, a hammer piston in the piston chambercontrolling the exhaust port and having a blower passage, an automaticvalve for distributing pressure fluid to the piston chamber, a spring inthe casing, a plug in the casing to actuate the spring against the valvefor holding the valve in position to admit pressure fluid into the frontend of the piston chamber and to the blower pas sage, said plug havinga. groove for engagement with the spring to retain the plug in thecasing, a passage in the casing opening into the rear end of the pistonchamber,

, "and a passage in the plug to register. with the passage. in thecasing for admitting pressure fluid into the rear end of the pistonchamber during the blowingoperation to maintain the piston inanintermediate position in the piston chamber for closing the exhaustport.

2. A fluid actuated rock drill comprising I a casing having a pistonchamber and an exhaust port, a hammer piston in the'piston chambercontrolling the exhaust port and having a, blower passage, an automaticvalve for distributing pressure fluid; to the piston chamber,v arecess'in the casing," a U-shaped spring in the recess and having

